What are the causes of Locked-In Syndrome (LIS)?

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Last updated: April 20, 2025View editorial policy

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From the Research

Locked-in syndrome is primarily caused by damage to the pons, a part of the brainstem that contains nerve fibers connecting the cerebrum to the spinal cord and cerebellum, with the most common cause being a stroke affecting the basilar artery, as reported in a recent study 1. The damage specifically affects the motor pathways while preserving consciousness and cognitive function, resulting in complete paralysis except for vertical eye movements and blinking, which remain intact. This occurs because the damage is located below the centers controlling consciousness but above the spinal cord, effectively disconnecting the brain's motor commands from the body while leaving sensory pathways and higher brain functions intact. Some of the key causes of locked-in syndrome include:

  • Stroke affecting the basilar artery
  • Traumatic brain injury
  • Brain hemorrhage
  • Infection (particularly encephalitis)
  • Tumors in the brainstem region
  • Demyelinating diseases like multiple sclerosis
  • Certain neurodegenerative disorders
  • Medication overdose, particularly from certain sedatives or anesthetics, can temporarily induce a locked-in state, as noted in a study from 2. Early recognition is crucial for appropriate management and establishing communication systems for affected individuals, as highlighted in a study on rehabilitation management 3. The prognosis of locked-in syndrome is generally poor, with most patients remaining locked in and having a poor quality of life, especially in terms of motor functions, as reported in a systematic review 1. However, with specialized rehabilitative care and access to the proper equipment, long-term outcomes and quality of life in these patients can be favorable, as noted in a study on rehabilitation management 3. It is essential to provide education and support to patients and their families, allowing them to develop a realistic understanding of the likely outcomes of their decisions, as suggested in a study on end-of-life decision-making 4.

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This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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